Expandable Tubular Technology is a new technology which emerged and was developed in the 1990s, and is applicable to operation processes, such as drilling, completion, oil production, workover and the like, and is touted as a new technology that can bring about a transformative development. The so-called expandable tubular is a metallic circular tubular made of special materials, its original state has a good extensibility, and its inner and outer diameters are expanded and are subjected to permanent plastic deformation with an expansion rate of from 15% to 30% by the pressing action of the expansion cone under the action of the expansion force. The expandable tubular technology changes a crystal structure and mechanical properties of the expandable tubular material by implementing tubular expanding operations of the expandable tubular so that its strength index is improved, while its plasticity index is decreased. The expandable tubular technology can allow an expandable tubular to obtain mechanical performance indices equivalent to those of a specific steel casing by technical means of selecting the expandable tubular material, controlling the expansion rate, and the like, so as to meet operational requirements of petroleum engineering.
The expandable tubular technology can be generally used to solve the problems caused by complex formations, e.g., blocking a serious thirsty formation to solve the problem of wellbore collapse; and the technology can also be used for casing patch and repair. According to the use of the expandable tubular technology, it can be classified into plural major technical systems, such as a casing patch system, an openhole system, an expandable tail tubular suspension system, a diameter-equivalent drilling and completion system, and the like.
The openhole system of the expandable tubular refers to a technology of adding a section (or a plurality of sections) of expandable tubular for isolation of a defective layer section between casing series initially commonly used in the openhole section, when drilling the defective openhole section in the drilling process. Under normal circumstances, the well crews can take technical measures of running casing in advance to solve the drilling problem, its result would lead to a series of associated technical problems, and even affect drilling of the final destination layer due to disruption of the casing sequence specified in the original drilling design. The openhole system technology of the expandable tubular utilizes addition of expandable tubular between the casing series initially commonly used, so that a drift diameter of the borehole has almost no loss after the construction operations are completed, which thus not only achieves the objective of dealing with down-hole troublesome conditions, but also can ensure a normal proceeding of the follow-up drilling construction. However, the existing domestic expandable tubular technology has an expansion rate of the expandable tubular of only 10% or so, a serious loss arises in the drift diameter of the borehole, and the original drilling head cannot continue to drill through after constructions with the expandable tubular, thereby affecting follow-up drilling operations.
Accordingly, the present inventors have developed a mechanical and hydraulic dual-effect expansion device for well drilling with expandable tubular technology with almost no loss of a drift diameter of a borehole according to years of experience in design and production engaged in this field and the related fields, so as to solve the existing technical problems.